Physical quantity detection device

Abstract

The present invention provides a physical quantity detection device capable of detecting load information and a lateral acceleration for each wheel, achieving independent damper control for each of four wheels, and providing a lateral force calculated highly accurately, the load information including not only a vehicle weight but also occupant and loading weights. A physical quantity detection device according to the present invention calculates a lateral force by using a load detected in actuality by a strain sensor and a lateral G detected from the characteristics of a sensor signal waveform. The load is detected from the magnitude of a strain peak amplitude, and the lateral G is detected from a difference in magnitude of the strain peak amplitude between turning (when lateral G is applied) and straight-ahead driving.

Description

[Technical Field]

[0001] The present invention relates to a physical quantity detection device that detects lateral acceleration, lateral force, etc. acting on a tire. [Background technology]

[0002] In recent years, in order to realize autonomous driving, tire sensor technology has been actively developed to provide safer driving conditions by detecting factors such as road surface slipperiness and tire load based on information obtained from tires. Providing safer driving conditions will prevent accidents caused by tire problems such as bursts due to overloading, or poor cornering due to reduced tire grip. Meanwhile, improving ride comfort through suspension control and other measures is also an important element of safety support. To build such a safety control system, it is necessary to accurately detect physical quantities such as load and lateral acceleration detected by tire sensors.

[0003] The tire strain sensor can detect the load and lateral acceleration acting on the tire by detecting the strain and deformation of the tire, and can also estimate the lateral force from the load and lateral acceleration detected. This is expected to improve driving safety by preventing vehicle troubles and accidents.

[0004] A strain sensor detects changes in various physical quantities (e.g., vehicle speed, temperature, air pressure, load, lateral acceleration, etc.) as strain. Therefore, the detection signal (strain signal) that represents the results of strain detected by the strain sensor may contain components caused by these physical quantities. When detecting a specific physical quantity based on the correspondence between the specific physical quantity and the strain signal, the accuracy of detecting the specific physical quantity decreases due to the components caused by these other physical quantities.

[0005] The following Patent Document 1 describes a technology for improving ride comfort using suspensions. The document describes the following technology: "A suspension control device for controlling the operation of a vehicle's suspension includes an operation-induced state quantity estimator that estimates an operation-induced state quantity that represents behavior due to vehicle operation; a road-surface-induced state quantity estimator that estimates a road-surface-induced state quantity that represents behavior of the vehicle due to the road surface; an operation-induced state quantity converter that converts the operation-induced state quantity into an operation-induced requested damping force; a road-surface-induced state quantity converter that converts the road-surface-induced state quantity into a road-surface-induced requested damping force; and a current value calculator that determines a current value to be applied to the suspension using the operation-induced requested damping force and the road-surface-induced requested damping force. The system employs a mechanism for improving ride comfort and drivability by controlling dampers for operation-induced state quantities (vehicle behavior due to sudden acceleration or cornering caused by driver operation). The damper control is calculated from longitudinal and lateral forces; for example, lateral force is calculated from F (lateral force) = m (mass) x a (lateral acceleration)." [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2022-84474 Summary of the Invention [Problem to be solved by the invention]

[0007] The technology described in Patent Document 1 employs a mechanism for improving ride comfort and drivability through damper control of operation-induced state variables (vehicle behavior due to sudden acceleration or cornering caused by driver operation). The damper control is calculated from longitudinal and lateral forces. For example, lateral force is calculated from F (lateral force) = m (mass) x a (lateral acceleration). However, because lateral force F is calculated using mass m and the vehicle weight stored in memory, the load of passengers and cargo may be insufficient, potentially resulting in poor lateral force calculation accuracy. Furthermore, while it is desirable for damper control to be able to independently control each of the four wheels, the lateral force is calculated using the acceleration of the vehicle's center of gravity and a fixed amount of vehicle weight, which raises concerns that the lateral force corresponding to the load on each of the four wheels may not be calculated. Therefore, it is believed that the technology described in this document has room for improvement in terms of the accuracy of lateral force calculation.

[0008] In view of the above circumstances, an object of the present invention is to provide a physical quantity detection device that can provide lateral forces independently for four wheels and that can provide lateral forces with high calculation accuracy. [Means for solving the problem]

[0009] A representative example of the inventions disclosed in the present application can be briefly outlined as follows: A physical quantity detection device according to one idea of ​​the present invention detects at least one of lateral G and lateral force acting on a tire from a strain sensor installed in the tire, the physical quantity detection device comprising: a load detection calculation unit that detects a load acting on the tire from a negative peak value of a sensor signal waveform output by the strain sensor that changes negatively with respect to a reference level when the tire is not in contact with the road surface; a lateral G detection calculation unit that distinguishes between the sensor signal waveform when the tire is traveling straight and the sensor signal waveform when the tire is turning, and detects the lateral G acting on the tire from an amount of change in the sensor signal waveform between when the tire is traveling straight and when the tire is turning, in the negative peak value that changes negatively with respect to the reference level when the tire is not in contact with the road surface; and a lateral force detection calculation unit that detects the lateral force acting on the tire from the product of the load detected by the load detection calculation unit and the lateral G detected by the lateral G detection calculation unit. [Effects of the Invention]

[0010] The physical quantity detection device according to the present invention can estimate the load from the negative peak value of the strain signal output by the sensor element, which changes negatively relative to the reference level, and can estimate the lateral G (lateral acceleration) from the amount of change in the signal waveform of the negative peak value when the tire is traveling straight and when turning. Furthermore, the lateral force can be estimated from the load and lateral G (lateral acceleration) using the formula lateral force F = detected load m x lateral acceleration a. In other words, the load and lateral G can be detected for each strain sensor installed in the tire, and independent system control of four wheels can be achieved through highly accurate lateral force detection from realistic (detected in real time) load and lateral G.

[0011] Further features related to the present invention will become apparent from the description of the present specification and the accompanying drawings. In addition, problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a configuration diagram showing a vehicle equipped with a physical quantity detection device according to a first embodiment. [Figure 2] 1 is a configuration diagram showing a physical quantity detection device according to a first embodiment. [Figure 3] 3 is an explanatory diagram showing a sensor signal waveform of a strain sensor according to a rotation state of a tire according to the first embodiment. FIG. [Figure 4] FIG. 3 is a waveform diagram showing a sensor signal waveform of a strain sensor according to the rotation state of a tire according to the first embodiment. [Figure 5] FIG. 3 is an explanatory diagram showing a sensor signal waveform of a strain sensor in one period according to the first embodiment. [Figure 6A] FIG. 2 is an explanatory diagram showing an outline of lateral G detection (an outline of lateral G of a right front wheel when turning left) according to the first embodiment. [Figure 6B] 4 is an explanatory diagram showing an outline of lateral G detection (sensor signal waveform of a strain sensor when turning left) according to the first embodiment; FIG. [Figure 7]FIG. 4 is an explanatory diagram showing the relationship between a reference waveform, a load estimation waveform, and a lateral G detection waveform according to the first embodiment. [Figure 8] 4 is a flowchart for deriving a table of parameters mixed in a sensor signal waveform of the strain sensor according to the first embodiment. [Figure 9] 4 is an explanatory diagram showing a speed correlation table indicating the correlation between speed and the amount of correction for peak values ​​at negative levels of the sensor signal waveform of the strain sensor according to the first embodiment; FIG. [Figure 10] 4 is an explanatory diagram showing a temperature correlation table indicating the correlation between the temperature and the amount of correction for the peak value of the negative level of the sensor signal waveform of the strain sensor according to the first embodiment; FIG. [Figure 11] 4 is an explanatory diagram showing an air pressure correlation table indicating the correlation between air pressure and the correction amount for the peak value of the negative level of the sensor signal waveform of the strain sensor according to the first embodiment; FIG. [Figure 12] FIG. 2 is an explanatory diagram showing a table including various tables according to the first embodiment. [Figure 13] 4 is a flowchart for estimating a load and a lateral G from a sensor signal waveform of a strain sensor according to the first embodiment. [Figure 14] 10 shows the results of verifying whether the strain sensor according to the first embodiment can estimate a load. [Figure 15] FIG. 3 is an explanatory diagram showing a first table of parameters mixed in a sensor signal waveform of the strain sensor according to the first embodiment. [Figure 16] 10 shows the results of verifying whether the strain sensor according to the first embodiment can estimate lateral G. [Figure 17] FIG. 10 is a configuration diagram showing a physical quantity detection device according to a second embodiment. [Figure 18A] FIG. 10 is an explanatory diagram showing an outline of lateral G detection according to the second embodiment (an outline of lateral G of the right front wheel when turning left). [Figure 18B] 10 is an explanatory diagram showing an outline of lateral G detection according to the second embodiment (sensor signal waveform of the strain sensor 1 when turning left). FIG. [Figure 18C]10 is an explanatory diagram showing an outline of lateral G detection according to the second embodiment (sensor signal waveform of the strain sensor 2 when turning left). FIG. [Figure 19] FIG. 10 is a configuration diagram showing a physical quantity detection device according to a third embodiment. [Figure 20A] FIG. 10 is an explanatory diagram showing the arrangement of strain sensors according to the third embodiment (overview of lateral G of the left front wheel when turning right). [Figure 20B] FIG. 10 is an explanatory diagram showing the arrangement of strain sensors according to the third embodiment (overview of lateral G of the right front wheel when turning left). [Figure 21] 10 is a flowchart illustrating a process of using lateral force detection information from a strain sensor for damper control according to the fourth embodiment. [Figure 22A] FIG. 11 is an explanatory diagram of the grip force due to damper control executed based on lateral force information according to the fourth embodiment (decrease in grip force without damper control). [Figure 22B] FIG. 11 is an explanatory diagram of grip force (improvement of grip force when damper control is performed) due to damper control executed based on lateral force information according to the fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In all drawings used to explain the embodiments, the same components are generally designated by the same reference numerals, and repeated explanations thereof will be omitted. The present invention should not be interpreted as being limited to the description of the embodiments shown below. Those skilled in the art will readily understand that the specific configuration can be changed within the scope of the idea or intent of the present invention.

[0014] The designations "first," "second," "third," etc. in this specification are used to identify components and do not necessarily limit the number or order. Furthermore, numbers used to identify components are used in different contexts, and numbers used in one context do not necessarily indicate the same configuration in another context. Furthermore, this does not prevent a component identified by a certain number from also serving the function of a component identified by another number.

[0015] In order to facilitate understanding of the invention, the position, size, shape, range, etc. of each component shown in the drawings etc. may not represent the actual position, size, shape, range, etc. Therefore, the present invention is not necessarily limited to the position, size, shape, range, etc. disclosed in the drawings etc.

[0016] As used herein, elements referred to in the singular are intended to include the plural unless the context clearly indicates otherwise.

[0017] [First embodiment] <Overall vehicle configuration> FIG. 1 is a configuration diagram showing a vehicle 100 equipped with a physical quantity detection device 10 according to a first embodiment. As shown in FIG. 1, the vehicle 100 includes four tires 101, one ECU 102, and one reporting unit 103. The vehicle 100 also includes four temperature sensors 2 and four strain sensors 3. Note that the vehicle 100 is not limited to a four-wheeled vehicle that travels on a road surface 20 (FIG. 3), but may also be a two-wheeled vehicle, a three-wheeled vehicle, or a vehicle with five or more wheels.

[0018] The vehicle 100 travels on a road surface 20 by rotating four tires 101. A person rides in the vehicle 100.

[0019] The tire 101 is in contact with the road surface 20 and receives the load of the vehicle 100. The tire 101 rotates. The tire 101 is a rubber member.

[0020] The ECU 102 is a control unit that controls the vehicle 100. The ECU 102 has an arithmetic processing unit, a storage unit, and an input / output port electrically connected to various sensors, an arithmetic processing unit such as a CPU, a storage unit such as a memory, and the reporting unit 103.

[0021] The reporting unit 103 is a monitor of the car navigation system. The display screen of the reporting unit 103 is switched between a car navigation screen and a report screen for lateral G, lateral force, etc., by interrupt processing from the ECU 102. The display of the display screen of the reporting unit 103 is controlled based on the control of the ECU 102.

[0022] The temperature sensor 2 acquires the temperature of each tire 101 and outputs it to the ECU 102. The strain sensor 3, which is a sensor element, acquires a sensor signal waveform 15 (see FIG. 3, etc.) in each tire 101 and outputs it to the ECU 102. Note that the strain sensor 3 can also detect the temperature of each tire 101 instead of the temperature sensor 2.

[0023] <Physical quantity detection device 10> 2 is a configuration diagram showing a physical quantity detection device 10 according to a first embodiment. The physical quantity detection device 10 relates to a safe driving support device for a vehicle 100, and in particular, is intended to prevent accidents caused by insufficient brake control by providing a safe driving state. The physical quantity detection device 10 is a device that detects load, lateral G, and the like that affect the durability and grip of tires 101 mounted on the vehicle 100.

[0024] 2, the physical quantity detection device 10 includes a strain sensor 3, a lateral G detection calculation unit 4, a memory unit 411, a load detection calculation unit 6, a lateral force detection calculation unit 7, and a reporting unit 103. The physical quantity detection device 10 detects the lateral G and lateral force of the tire 101 based on the output signal waveform. The physical quantity detection device 10 is independently installed in each of the four tires 101, and the lateral G and lateral force of each tire are shared by the common reporting unit 103 and used for system control.

[0025] <Strain sensor 3> The strain sensor 3 is a sensor element. The strain sensor 3 is a semiconductor, and converts a change in resistance into a strain amount and outputs the converted amount. One strain sensor 3 is disposed in each tire 101. The strain sensor 3 outputs a sensor signal waveform 15 having a reference level 151, a positive level that changes to the positive side of the reference level 151, and a negative level that changes to the negative side of the reference level 151 (see FIG. 3, etc.).

[0026] <Lateral G detection calculation unit 4> The lateral G detection calculation unit 4 performs the function of the lateral G detection calculation unit 4 by executing a program in the ECU 102. The lateral G detection calculation unit 4 receives the sensor signal waveform 15 output by the strain sensor 3.

[0027] The lateral G detection calculation unit 4 acquires the temperature of the tire 101 from the temperature sensor 2. The lateral G detection calculation unit 4 acquires the speed by subtracting the tire circumference from the output period of the sensor signal waveform 15. The lateral G detection calculation unit 4 may also acquire the speed from a speed sensor or the like. The lateral G detection calculation unit 4 corrects the sensor signal waveform 15 output by the strain sensor 3 according to the acquired parameter conditions such as temperature and speed, and estimates the lateral G, etc. from the difference between this corrected signal and a reference waveform (reference value) stored in the memory unit 411. The lateral G detection calculation unit 4 transmits the estimated lateral G, etc. to the reporting unit 103 and the lateral force detection calculation unit 7.

[0028] The lateral G detection calculation unit 4 has a correction unit 412 and a lateral G calculation unit 413.

[0029] The storage unit 411 has a first table 5 containing reference waveforms (peak values ​​of positive level, peak values ​​of negative level, reference levels) acquired under reference conditions (air pressure, temperature, speed) of the sensor signal waveform 15 output by the strain sensor 3, and the amount of change for each parameter condition. The acquired data is, for example, data on an asphalt road surface.

[0030] The correction unit 412 determines whether lateral G is occurring from the difference between the negative peak values ​​of the sensor signal waveform 15 when traveling straight and when turning, and extracts the lateral G component. The correction unit 412 can also correct the signal waveform under predetermined conditions using the values ​​of the first table 5 stored in the storage unit 411 so as to cancel the difference between the tire pressure, speed, and temperature, which are parameters of the mixed signal mixed in the sensor signal waveform 15, and the reference conditions. The correction unit 412 transmits the extracted lateral G component to the lateral G calculation unit 413.

[0031] Lateral G calculation unit 413 compares positive level peak value 152, negative level peak value 153, and reference level 151 of the lateral G component signal transmitted by correction unit 412 with the correlation characteristics for each parameter condition stored in first table 5 stored in memory unit 411, and estimates lateral G from the characteristic difference with negative level peak value 153. Lateral G calculation unit 413 transmits the estimated lateral G to report unit 103 and lateral force detection calculation unit 7.

[0032] <Load detection calculation unit 6> The load detection calculation unit 6 performs the function of the load detection calculation unit 6 by executing a program in the ECU 102, similar to the lateral G detection calculation unit 4. The load detection calculation unit 6 receives the sensor signal waveform 15 output by the strain sensor 3.

[0033] The load detection calculation unit 6 has a load correction unit 611 and a load calculation unit 612, similar to the lateral G detection calculation unit 4.

[0034] As explained in the lateral G detection calculation unit 4, the storage unit 411 has a first table 5 for the reference waveform (peak value of the positive level, peak value of the negative level, reference level) acquired under the reference conditions (air pressure, temperature, speed) of the sensor signal waveform 15 output by the strain sensor 3, and the amount of change for each parameter condition. This first table 5 is shared and used for correction calculation.

[0035] The load correction unit 611 determines the amount of correction from the negative level peak value of the sensor signal waveform 15 when traveling straight. The load correction unit 611 also corrects the air pressure, speed, and temperature, which are parameters of a mixed signal mixed in the sensor signal waveform 15, from the values ​​in the first table 5 stored in the memory unit 411 to a signal waveform under predetermined conditions so as to cancel the difference from the reference conditions, and transmits the corrected signal waveform to the load calculation unit 612.

[0036] The load calculation unit 612 compares the positive level peak value 152, the negative level peak value 153, and the reference level 151 of the corrected signal waveform transmitted by the load correction unit 611 with the correlation characteristics for each parameter condition stored in the first table 5 stored in the storage unit 411, and estimates the load from the characteristic difference with the negative level peak value 153. The load calculation unit 612 transmits the estimated load to the lateral force detection calculation unit 7.

[0037] <Lateral force detection calculation unit 7> The lateral force detection calculation unit 7 estimates the lateral force by integrating the load estimated by the load detection calculation unit 6 and the lateral G estimated by the lateral G detection calculation unit 4. The lateral force detection calculation unit 7 transmits the estimated lateral force to the reporting unit 103.

[0038] <Sensor signal waveform 15> 3 is an explanatory diagram showing a sensor signal waveform 15 of the strain sensor 3 according to the rotation state of the tire 101 according to the first embodiment. As shown in FIG. 3, the strain sensor 3 disposed inside the tire 101 outputs a sensor signal waveform 15 that changes depending on the state of the rotating tire 101.

[0039] The strain sensor 3 outputs a sensor signal waveform 15 having a reference level 151, a positive level that changes to the positive side of the reference level 151, and a negative level that changes to the negative side of the reference level 151.

[0040] The strain sensor 3 maintains the reference level 151 of the sensor signal waveform 15 when the tire 101 is not in contact with the road surface 20. The strain sensor 3 outputs a positive level peak value 152 of the sensor signal waveform 15 when the tire 101 (the portion of the tire where the strain sensor 3 is installed) is in contact with the road surface 20. The strain sensor 3 outputs a negative level peak value 153 of the sensor signal waveform 15 at the moment when the tire 101 (the portion of the tire where the strain sensor 3 is installed) touches or separates from the road surface 20. Here, the moment when the tire 101 touches or separates from the road surface 20 is the sensor displacement point. The period between two sensor displacement points is a contact period when the tire 101 (the portion of the tire where the strain sensor 3 is installed) is in contact with the road surface 20.

[0041] The sensor signal waveform 15 thus detected varies depending on various physical quantities (load, air pressure, speed, temperature).

[0042] FIG. 4 is a waveform diagram showing the sensor signal waveform 15 of the strain sensor 3 according to the rotation state of the tire 101 according to the first embodiment. As shown in FIG. 4, as the tire 101 rotates, the sensor signal waveform 15 of the strain sensor 3 alternates between a reference level 151, a negative level that changes to a negative side relative to the reference level 151, a positive level that changes to a positive side relative to the reference level 151, and a negative level that changes to a negative side relative to the reference level 151. The signal value of the sensor signal waveform 15 can be expressed by a signal amplitude. In FIGS. 3 and 4, the sensor signal waveform 15 is also expressed by a signal amplitude. The signal amplitude here may be any value that represents the amplitude of the sensor signal waveform 15. The sensor signal waveform 15 has a waveform in which a falling waveform is successively formed before and after a rising waveform, as shown in FIG. 5. For example, the amplitude of the second falling waveform can be treated as the amplitude of the sensor signal waveform 15. This is assumed below.

[0043] Fig. 5 is an explanatory diagram showing a sensor signal waveform 15 of the strain sensor 3 in one cycle according to the first embodiment. Fig. 5 is an enlarged view of part A in Fig. 4. As shown in Fig. 5, a reference level 151 contains information about the pressure (air pressure), a peak value (sometimes referred to as a positive peak value) 152 of the positive level contains information about wear, and a peak value (sometimes referred to as a negative peak value) 153 of the negative level contains information about the load and lateral G.

[0044] <Lateral G-force detection image (overview)> 6A and 6B are explanatory diagrams showing an image of lateral G-force detection. As shown in FIG. 6A, a tire 101 mainly comprises a sidewall portion 111 and a tread portion 112, and a strain sensor 3 is disposed inside (on the tire's inner surface) of the surface (tire tread surface) of the tread portion 112, particularly outside the center of the tire's inner surface of the tire tread surface. FIG. 6B shows a sensor signal waveform 15 of the strain sensor 3 when turning left. When switching from straight driving to turning, the negative level peak value increases, and lateral G-force is detected from the correlation between this increase and the amount of lateral G-force.

[0045] Figure 7 is an explanatory diagram showing how a correction method for removing physical quantities mixed in the distortion signal applies to lateral G detection. Lateral G detection expresses the peak value of the negative level as the difference between the peak values ​​when driving straight and when turning. First, to determine the load, the reference waveform is compared with the corrected waveform when the load increases to detect the load. At this time, the mixed physical quantities (air pressure, temperature, vehicle speed) are removed by correction to extract only the load information. Next, the waveform of the increased load, from which the mixed signals have been removed, is compared with the waveform when turning, and the lateral G component is extracted from the difference. Therefore, by calculating the difference between the physical quantities mixed in the distortion signal contained in the peak values ​​when turning and when driving straight, it is possible to cancel them. Note that load information is required to calculate the lateral force, and for highly accurate load detection, a correction process is performed to cancel the mixed signal.

[0046] <How to create Table 15> FIG. 8 is a flowchart for deriving the first table 5 that stores the correlation between the sensor signal waveform 15 of the strain sensor 3 according to the first embodiment and the peak value of the negative level under each condition including the reference condition.

[0047] As shown in Figure 8, in S101, a predetermined control unit (not shown) for table creation testing maintains the reference air pressure, temperature, speed, load, and lateral G, drives the vehicle 100 in a straight line and turns, and acquires the output of the strain sensor 3 for the reference conditions. For load detection, the peak value of the negative level when driving in a straight line is defined as the reference waveform. For lateral G detection, the difference between the peak values ​​of the negative level when driving in a straight line and when turning is defined as the reference waveform.

[0048] In S102, the control unit acquires a relationship representing the change from the reference waveform for the negative level peak value 153 of the sensor signal waveform 15 of the strain sensor 3 when the vehicle 100 is driven while changing each of the reference air pressure, temperature, speed, load, and lateral G.

[0049] In S103, the control unit stores in the first table 5 the reference waveform and the amount of change thereof for the sensor signal waveform 15 acquired in S102.

[0050] The change in sensor signal waveform 15 when each condition changes does not necessarily have to be expressed using the difference from the reference and the difference from the reference signal value. However, since the absolute value of the signal value differs for each vehicle model and tire type, it becomes necessary to create data similar to first table 5 for each absolute value in advance, which would significantly increase the amount of data. Therefore, by describing the data using the difference from the reference value, the amount of data is reduced.

[0051] The correlations between the negative level peak value 153 of the sensor signal waveform 15 of the strain sensor 3 and the air pressure, temperature, and speed were stored in advance as a table in the storage unit 411 by varying these values.

[0052] 9 is an explanatory diagram showing a speed correlation table of the first table 5 indicating the correlation between the speed and the amount of correction for the peak value 153 at the negative level of the sensor signal waveform 15 of the strain sensor 3 according to the first embodiment. The table shown in FIG. 9 shows a correlation in which the amount of correction for the peak value 153 at the negative level of the sensor signal waveform 15 increases as the speed increases.

[0053] 10 is an explanatory diagram showing a temperature correlation table of the first table 5 indicating the correlation between the temperature and the correction amount of the peak value 153 at the negative level of the sensor signal waveform 15 of the strain sensor 3 according to the first embodiment. The table shown in FIG. 10 shows a correlation in which the correction amount of the peak value 153 at the negative level of the sensor signal waveform 15 increases as the temperature increases.

[0054] 11 is an explanatory diagram showing the air pressure correlation table of the first table 5, which shows the correlation between the air pressure and the correction amount for the peak value 153 at the negative level of the sensor signal waveform 15 of the strain sensor 3 according to the first embodiment. The table shown in FIG. 11 shows a correlation in which the correction amount for the peak value 153 at the negative level of the sensor signal waveform 15 decreases as the air pressure increases.

[0055] Fig. 12 is an explanatory diagram showing the first table 5 including various tables according to the first embodiment. As shown in Fig. 12, the first table 5 includes the reference table of the first embodiment and the various correlation tables of Figs. 9 to 11. Therefore, the correction amounts for load detection and lateral G detection are estimated from the first table 5 stored in the storage unit 411 for the negative-level peak value 153 of the sensor signal waveform 15 output by the strain sensor 3 in the vehicle 100 while it is traveling in various ways.

[0056] <Lateral G detection method> FIG. 13 is a flowchart for estimating the load and lateral G acting on the tire 101 when it is traveling from the sensor signal waveform 15 of the strain sensor 3 according to the first embodiment.

[0057] The flow chart of the load and lateral G detection method shown in FIG. 13 is repeatedly executed at a certain period while the vehicle 100 is traveling.

[0058] When the load and lateral G detection method is performed, in S201, the lateral G detection calculation unit 4 checks the driving conditions in the driving state of the vehicle 100 using the correction unit 412. The driving conditions are conditions that match the driving conditions when deriving the first table 5. When the driving conditions are checked using the correction unit 412 in S201, the process proceeds to S202.

[0059] In S202, a corrected signal waveform for load estimation is obtained from the waveform during straight-ahead driving. In order to correct the sensor signal waveform 15 output by the strain sensor 3 to a signal waveform under the same reference conditions as the reference waveform, the load detection calculation unit 6 obtains a correction amount from the correlation diagram of air pressure, temperature, and speed derived in the first table 5, and subtracts this from the output sensor signal waveform 15 to obtain a corrected signal waveform. After processing in S202, the process proceeds to S203.

[0060] In S203, the load detection calculation unit 6 estimates the load based on the result of comparing the corrected signal waveform obtained in S202 with the reference waveform. First, the difference between the corrected signal waveform of the negative peak value and the reference waveform is compared with the load correlation diagram in the first table 5, and the load corresponding to this difference is estimated each time. The load is transmitted to the lateral force detection calculation unit 7. After processing in S203, the process proceeds to S204.

[0061] In S204, the correction unit 412 determines the lateral G force. The difference between the peak value 153 of the negative level of the sensor signal waveform 15 when traveling straight and when turning is confirmed, and if the difference changes by 10% or more, it is determined that lateral G force has occurred, and the process proceeds to S205. If No, the straight traveling data continues to be collected.

[0062] In S205, the lateral G detection calculation unit 4 compares the negative level peak value 153 of the sensor signal waveform 15 detected by the strain sensor 3 when traveling straight with the negative level peak value 153 when determining a turn. When detecting lateral G, the difference between traveling straight and when turning is taken, so the mixed signal can be canceled out and no correction is required. After processing in S205, the process proceeds to S206.

[0063] In S206, the difference between the reference waveform during cornering and the negative-level peak value 153 of the sensor signal waveform 15 is first calculated. Next, the difference is compared with the correlation diagram of lateral G in the first table 5 for each cornering, and the lateral G corresponding to this difference is estimated. The lateral G estimated here is then calculated from the load estimated in S203, and the lateral G and lateral force are transmitted to the reporting unit 103. After the processing of S206, the processing temporarily ends.

[0064] <Verification of lateral G-force detection method> The verification of the load detection method and lateral G detection method will be described in turn.

[0065] FIG. 14 shows the results of verifying whether load estimation can be performed according to the flowchart of FIG. 13 based on an example of an actual measured sensor signal waveform of the strain sensor 3 according to the first embodiment. FIG. 14 shows the load sensitivity of the negative-level peak value 153 in the sensor signal waveform 15 of the strain sensor 3 under reference conditions (air pressure, temperature, speed). It also shows the speed sensitivity. As the load increases, the negative-level peak value 153 decreases linearly (monotonically decreases), demonstrating that it is possible to construct the first table 5 shown in the flowchart. It can also be confirmed that the speed changes at a substantially fixed value relative to the load.

[0066] FIG. 15 is an explanatory diagram showing a first table 5 of parameters mixed in the sensor signal waveform 15 of the strain sensor 3 according to the first embodiment. As shown in FIG. 15, the correlation diagram of air pressure, temperature, and speed in the first table 5 is a proportional correlation graph in which the same correction amount is obtained regardless of how the load changes with respect to the sensor signal waveform 15. This is because air pressure, temperature, and speed are insensitive to the load and show constant values. The first table 5 is stored in the memory unit 411. The first table 5 is derived by subtracting the correction amounts of various physical quantities, which are mixed together in the lines for air pressure correction, speed correction, and temperature correction, from the line of the reference level 151 of the apparent sensor signal waveform 15, to obtain the line of the actually desired load.

[0067] 16 shows the results of verifying whether lateral G can be estimated according to the flowchart of FIG. 13 based on an example of an actual sensor signal waveform of the strain sensor 3 according to the first embodiment. FIG. 16 shows the lateral G sensitivity of the negative-level peak value 153 in the sensor signal waveform 15 of the strain sensor 3 under reference conditions. As the lateral G increases, the difference in the negative-level peak value 153 decreases linearly (monotonically decreases), indicating that it is possible to construct the first table 5 shown in the flowchart. Note that FIG. 16 shows a case in which the difference in the negative-level peak value 153 with respect to the lateral G (the peak difference between traveling straight and turning) decreases linearly (monotonically decreases). However, the same applies to a case in which the difference in the negative-level peak value 153 with respect to the lateral G (the peak difference between traveling straight and turning) increases linearly (monotonically increases).

[0068] <Effects> As described above, the sensor signal waveform 15 output by the strain sensor 3 is corrected according to the conditions of parameters such as air pressure, temperature, and speed, the load is estimated according to the difference between this corrected signal waveform and the reference waveform (reference value) stored in the memory unit 411, and the lateral G is estimated from the difference (amount of change) between the sensor signal waveform 15 when traveling straight and when turning, thereby enabling the strain sensor 3 to detect the load and lateral G. Furthermore, the lateral force can be detected from the product of the load and lateral G.

[0069] [Second embodiment] The following describes an embodiment that is a modification of the above embodiment. The following describes a device that detects lateral G using a configuration in which the number of strain sensors arranged in the tire of the first embodiment is increased to two. Furthermore, since the overall configuration of the vehicle is the same as that of the first embodiment, a description thereof will be omitted.

[0070] <Physical Quantity Detection Device 2010> 17 is a configuration diagram showing a physical quantity detection device 2010 according to the second embodiment. The physical quantity detection device 2010 relates to a safe driving support device for the vehicle 100, and in particular, is intended to prevent accidents caused by insufficient brake control by providing a safe driving state. The physical quantity detection device 2010 is a device that detects load, lateral G, and the like that affect the durability and grip of the tires 101 mounted on the vehicle 100.

[0071] 17 , the physical quantity detection device 2010 includes a strain sensor 1 2003, a strain sensor 2 2031, a lateral G detection calculation unit 2004, a memory unit 2411, a load detection calculation unit 2006, a lateral force detection calculation unit 2007, and a reporting unit 2103. The physical quantity detection device 2010 detects the lateral G and lateral force of the tire 101 based on the output signal waveform.

[0072] The configurations and operations of the lateral G detection calculation unit 2004, the load detection calculation unit 2006, etc. are the same as those in the first embodiment, and therefore will not be described. Furthermore, the table creation method and lateral G detection method are also the same as those in the first embodiment, and therefore will not be described.

[0073] <Lateral G-force detection image (overview)> 18A, 18B, and 18C are explanatory diagrams showing an image of lateral G detection. As shown in FIG. 18A, strain sensor 1 2003 is arranged on the inside of the interior (inner surface of the tire) of the surface (tire tread surface) of tread portion 112, and strain sensor 2 2031 is arranged on the outside. In other words, strain sensor 1 2003 and strain sensor 2 2031 are arranged on the left and right (of the center) on the inner surface of the tire tread surface. FIG. 18B shows the sensor signal waveform of strain sensor 1 2003 when turning left, and FIG. 18C shows the sensor signal waveform of strain sensor 2 2031. In the inner strain sensor 1 2003, the peak value of the negative level decreases when switching from straight driving to turning, and in the outer strain sensor 2 2031, the peak value of the negative level increases when switching from straight driving to turning. By taking the difference between this increase and decrease, the peak amount of the negative level can be increased, and the correlation between this increase and the amount of lateral G-force makes it possible to detect lateral G-force with high sensitivity.

[0074] <Effects> As described above, by determining lateral G from the correlation between the difference in the negative peak values ​​of the sensor signal waveforms of the two strain sensors installed separately on the left and right sides inside the tire, and further the increment in the peak values ​​when traveling straight and when turning (in other words, the further difference between the difference in the negative peak values ​​(amount of change between the increase and decrease) of the two strain sensors installed separately on the left and right sides inside the tire) and the amount of lateral G, in addition to the effects of the first embodiment, there is an effect of improving the detection sensitivity of lateral G.

[0075] [Third embodiment] The following describes an embodiment that is a modification of the above embodiment. In the following, a method will be described in which, in contrast to the device for detecting lateral G using a configuration in which two strain sensors are placed inside the tires of the second embodiment, one strain sensor is placed inside the tire and another strain sensor that measures the difference is placed in one of the left and right tires. Furthermore, because the overall vehicle configuration is assumed to be similar to that of the first embodiment, a description thereof will be omitted.

[0076] <Physical quantity detection devices 3010, 4010> 19 is a configuration diagram showing a physical quantity detection device 1 3010 for a left tire and a physical quantity detection device 2 4010 for a right tire according to the third embodiment. Strain sensor signals in both physical quantity detection devices are received as second sensor signals by the lateral G detection calculation unit 1 3004 and the lateral G detection calculation unit 2 4004. The physical quantity detection device 1 3010 and the physical quantity detection device 2 4010 relate to a safe driving support device for the vehicle 100, and in particular, are intended to prevent accidents due to insufficient brake control by providing a safe driving state. The physical quantity detection device 1 3010 and the physical quantity detection device 2 4010 are devices that detect load, lateral G, and the like that affect the durability and grip of the tires 101 mounted on the vehicle 100.

[0077] 19, the physical quantity detection device 1 3010 for the left tire includes a strain sensor 1 3003, a lateral G detection calculation unit 1 3004, a memory unit 1 3411, a load detection calculation unit 1 3006, a lateral force detection calculation unit 1 3007, and a reporting unit 3103. The physical quantity detection device 1 3010 detects the lateral G and lateral force of the left tire 101 based on the output signal waveform.

[0078] The configurations and operations of the lateral G detection calculation unit 1 3004, the load detection calculation unit 1 3006, etc. are the same as those in the first embodiment, and therefore will not be described. Also, the table creation method and the lateral G detection method are the same as those in the first embodiment, and therefore will not be described.

[0079] Like the physical quantity detection device 1 3010 for the left tire, the physical quantity detection device 2 4010 for the right tire includes a strain sensor 2 4003, a lateral G detection calculation unit 2 4004, a memory unit 2 4411, a load detection calculation unit 2 4006, a lateral force detection calculation unit 2 4007, and a reporting unit 3103. The physical quantity detection device 2 4010 detects the lateral G and lateral force of the right tire 101 based on the output signal waveform.

[0080] The configurations and operations of the lateral G detection calculation unit 2 4004, the load detection calculation unit 2 4006, etc. are the same as those in the first embodiment, and therefore will not be described. Also, the table creation method and the lateral G detection method are the same as those in the first embodiment, and therefore will not be described.

[0081] <Lateral G-force detection image (overview)> 20A and 20B are explanatory diagrams showing the arrangement of strain sensors in left and right tires. As shown in Fig. 20A, strain sensor 1 3003 is arranged on the outside of the inside (tire inner surface) of the surface (tire tread surface) of tread portion 112 of the left tire, and as shown in Fig. 20B, strain sensor 2 4003 is arranged on the outside of the inside (tire inner surface) of the surface (tire tread surface) of tread portion 112 of the right tire. When turning left, the lateral G force to the right front wheel (Fig. 20B) is determined from the peak amount of the signal waveform obtained by subtracting the sensor signal waveform of strain sensor 1 3003 from the sensor signal waveform of strain sensor 2 4003, and when turning right, the lateral G force to the left front wheel (Fig. 20A) is determined from the peak amount of the signal waveform obtained by subtracting the sensor signal waveform of strain sensor 2 4003 from the sensor signal waveform of strain sensor 1 3003. This makes it possible to increase the peak amount as in the second embodiment, and improve the detection sensitivity of lateral G.

[0082] <Effects> As described above, by determining lateral G from the correlation between the difference in the negative level peak values ​​of the sensor signal waveforms of the strain sensors installed on the outside inside the left and right tires, and the increment in the peak values ​​when traveling straight and when turning (in other words, the difference between the difference (amount of change) in the negative level peak values ​​of the (two) strain sensors installed inside the left and right tires, respectively, when traveling straight and when turning), in addition to the effect of the first embodiment, there is an effect of improving the detection sensitivity of lateral G.

[0083] [Fourth embodiment] The following describes an embodiment that is a modification of the above embodiment. A method for performing damper control to improve tire grip using the lateral force estimated in the first embodiment will be described below. Since the overall vehicle configuration is the same as that of the first embodiment, a description thereof will be omitted. Furthermore, since the physical quantity detection device, table creation method, and lateral G detection method are the same as those of the first embodiment, a description thereof will be omitted.

[0084] FIG. 21 is a flowchart showing a process of estimating the lateral force of the tire 101 when it is traveling from the sensor signal waveform 15 of the strain sensor 3 according to the fourth embodiment, and further controlling the damper.

[0085] The flowchart of the lateral force detection and damper control method shown in FIG. 21 is repeatedly executed at a certain period while the vehicle 100 is traveling.

[0086] As in FIG. 13 of the first embodiment, steps S401 to S406 are executed, and after determining the lateral G, the process proceeds to step S407.

[0087] In S407, the damper of the tire on the side where lateral G is occurring is controlled to a damper force corresponding to the lateral force. After control, processing of S407 is completed, and the processing ends for the time being.

[0088] 22A and 22B are explanatory diagrams outlining the improvement of grip through damper control executed based on lateral force information. FIG. 22A shows how grip decreases without damper control. It shows a state in which lateral G forces are generated to the right as the vehicle turns left. At this time, the center of gravity of the vehicle body shifts to the right due to the lateral G forces, causing it to tilt to the right, concentrating the vehicle weight on the right tire, which acts on it with a force greater than normal lateral force, potentially making it impossible for the tire's normal grip to support the force. In addition, the left tire receives less vehicle weight, which causes the tire to lift off the road surface, potentially reducing grip.

[0089] Figure 22B shows how grip is improved when damper control is enabled. Similarly, it shows a state in which the vehicle is turning left and lateral G forces are being generated in the right direction. At this time, the center of gravity of the vehicle body tends to shift to the right due to the lateral G forces, but damper control controls the damper force on the right side to a strength that corresponds to the magnitude of the lateral G forces, so the vehicle tilts less than when damper control is disabled. This prevents the concentration of vehicle weight on the right tire and balances the vehicle weight across all four wheels, improving the possibility that the vehicle will be supported by normal grip force. Furthermore, because the vehicle weight can also be balanced on the left tire, the force that causes the tire to lift off the road surface can be reduced, improving the possibility of preventing a decrease in grip force.

[0090] <Effects> As described above, by controlling the suspension or damper based on the lateral G or lateral force detected by the strain sensor 3, it is possible to change the balance of the tire's gripping force, thereby improving the possibility of preventing a decrease in tire gripping force.

[0091] [Summary of the first to fourth embodiments] As described above, the physical quantity detection devices 10, 2010, 3010, and 4010 of the present embodiment detect at least one of lateral G and lateral force acting on the tire 101 from a strain sensor installed on the tire 101, and include a load detection calculation unit 6 that detects a load applied to the tire 101 from a negative peak value (peak value of a negative level) 153 of a sensor signal waveform 15 output by the strain sensor that changes to a negative value with respect to a reference level 151 in a state where the tire 101 is not in contact with the road surface 20, and a load detection calculation unit 7 that calculates a load applied to the tire 101 from a negative peak value (peak value of a negative level) 153 of a sensor signal waveform 15 output by the strain sensor when the tire 101 is traveling straight. a lateral G detection calculation unit 4 that distinguishes between a sensor signal waveform 15 during a turn and a sensor signal waveform 15 during a turn, and detects a lateral G acting on the tire 101 from a change amount (difference) in the sensor signal waveform of a negative peak value (peak value of a negative level) 153 of the sensor signal waveform 15 that changes to a negative value with respect to the reference level 151 in a state in which the tire 101 is not in contact with the road surface 20, when the tire 101 is traveling straight and when the tire 101 is turning; and a lateral force detection calculation unit 7 that detects a lateral force acting on the tire 101 from a product of the load detected by the load detection calculation unit 6 and the lateral G detected by the lateral G detection calculation unit 4.

[0092] One strain sensor is installed on the tire tread surface on the inner surface of the tire, outside the center.

[0093] The difference (amount of change) between the negative peak values ​​of the sensor output waveform 15 when the tire 101 is traveling straight and when the tire 101 is turning monotonically increases or decreases with respect to the lateral G-force.

[0094] The strain sensors are installed in pairs, one on each side, on the inner surface of the tire tread surface, and the lateral G detection calculation unit 2004 obtains a difference between the amount of change (difference) in the sensor signal waveforms of the negative peak values ​​(negative level peak values) 153 of the two strain sensors when the tire 101 is traveling straight and when it is turning, and detects the lateral G from the difference (second embodiment). One of the two strain sensors is installed outside the center of the inner surface of the tire tread surface, and the other of the two strain sensors is installed inside the center of the inner surface of the tire tread surface (second embodiment).

[0095] The lateral G detection calculation unit 4 holds the lateral G sensitivity characteristics of the distortion peaks stored in the memory units 411, 2411, 3411, 4411 provided in the physical quantity detection devices 10, 2010, 3010, 4010 as a table (first table 5), and detects the lateral G by comparing the lateral G sensitivity characteristics of the distortion peaks.

[0096] The physical quantity detection devices 10, 2010, 3010, 4010 can also detect the air pressure of the tire 101 at the reference level 151 of the sensor signal waveform 15, and detect the load and wear of the tire 101 from the distortion signal corrected by the air pressure.

[0097] The strain sensors are installed on the inner surface of the tire tread surface of the tires 101 (left and right front wheels) arranged on the left and right sides of the front of the vehicle, and the lateral G detection calculation units 3004, 4004 further calculate the difference in the change (difference) in the sensor signal waveform of the negative peak values ​​(negative level peak values) 153 of the (two) strain sensors respectively installed on the tires 101 (left and right front wheels) arranged on the left and right sides of the front of the vehicle, when the tire 101 is traveling straight and when it is turning, and detect the lateral G from the difference (third embodiment).

[0098] The lateral G detection calculation unit 4 determines that the lateral G has occurred when the change (difference) in the negative peak value (negative level peak value) 153 when the tire 101 is traveling straight and when turning is 10% or more of the signal amplitude of the sensor signal waveform.

[0099] The lateral G detection and calculation unit 4 constantly compares the lateral G with the characteristics stored in a table (first table 5) and detects the lateral G in real time.

[0100] The physical quantity detection devices 10, 2010, 3010, and 4010 are applied to improving the ride comfort of a vehicle equipped with the tire 101 by performing suspension control based on the magnitude of the lateral G.

[0101] The physical quantity detection devices 10, 2010, 3010, 4010 change the balance of the gripping force of the tire 101 by damper control based on the magnitude of the lateral force, and are applied to safety support to prevent skidding of a vehicle equipped with the tire 101.

[0102] The physical quantity detection devices 10, 2010, 3010, and 4010 according to the present embodiment can estimate the load from the negative peak value of the strain signal output by the sensor element, which changes negatively relative to the reference level. The lateral G (lateral acceleration) can be estimated from the amount of change in the signal waveform of the negative peak value when the tire is traveling straight and when turning. Furthermore, the lateral force can be estimated from the load and lateral G (lateral acceleration) using the formula: lateral force F = detected load m x lateral acceleration a. In other words, the load and lateral G can be detected for each strain sensor installed in the tire, and independent system control of four wheels can be achieved by highly accurate lateral force detection from realistic (detected in real time) load and lateral G.

[0103] The present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and are not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with the configuration of another embodiment. [Explanation of symbols]

[0104] 2...Temperature sensor, 3...Distortion sensor, 4...Lateral G detection calculation unit, 5...First table, 6...Load detection calculation unit, 7...Lateral force detection calculation unit, 10...Physical quantity detection device, 15...Sensor signal waveform, 100...Vehicle, 101...Tire, 102...ECU, 103...Report unit, 151...Reference level, 152...Peak value of positive level, 153...Peak value of negative level, 411...Memory unit, 412...Correction unit, 413...Lateral G calculation unit, 611...Load correction unit, 612...Load calculation unit

Claims

1. A physical quantity detection device that detects at least one of a lateral G or a lateral force acting on a tire from a strain sensor installed in the tire, a load detection calculation unit that detects a load applied to the tire from a negative peak value of a sensor signal waveform output by the strain sensor that changes to a negative value with respect to a reference level when the tire is not in contact with a road surface; a lateral G detection and calculation unit that distinguishes between the sensor signal waveform when the tire is traveling straight and the sensor signal waveform when the tire is turning, and detects the lateral G acting on the tire from the amount of change in the sensor signal waveform when the tire is traveling straight and when the tire is turning, of the negative peak value of the sensor signal waveform that changes negatively with respect to the reference level when the tire is not in contact with the road surface; a lateral force detection calculation unit that detects a lateral force acting on the tire from the product of the load detected by the load detection calculation unit and the lateral G detected by the lateral G detection calculation unit.

2. 2. The physical quantity detection device according to claim 1, The physical quantity detection device is characterized in that one strain sensor is installed on the tire tread surface, outside the center of the inner surface of the tire.

3. 2. The physical quantity detection device according to claim 1, A physical quantity detection device, characterized in that the difference between the negative peak values ​​of the sensor signal waveform when the tire is traveling straight and when the tire is turning monotonically increases or monotonically decreases with respect to the lateral G.

4. 2. The physical quantity detection device according to claim 1, The strain sensors are installed in pairs on the left and right sides of the tire inner surface of the tire tread surface, The physical quantity detection device is characterized in that the lateral G detection calculation unit further calculates a difference in the amount of change in the sensor signal waveform of the negative peak values ​​of the two strain sensors when the tire is traveling straight and when the tire is turning, and detects the lateral G from the difference.

5. 2. The physical quantity detection device according to claim 1, The physical quantity detection device is characterized in that the lateral G detection calculation unit holds the lateral G sensitivity characteristics of distortion peaks stored in a memory unit provided in the physical quantity detection device as a table, and detects the lateral G by comparing the lateral G sensitivity characteristics of the distortion peaks with the table.

6. 2. The physical quantity detection device according to claim 1, The physical quantity detection device is characterized in that it is also possible to detect the air pressure of the tire at the reference level of the sensor signal waveform, and detect the load and wear of the tire from a distortion signal corrected by the air pressure.

7. 2. The physical quantity detection device according to claim 1, the strain sensors are installed on inner surfaces of the tire tread surfaces of the tires disposed on the left and right sides of the front of the vehicle, the lateral G detection calculation unit further calculates a difference in the amount of change in the sensor signal waveform of the negative peak value of a strain sensor installed on each of the tires disposed on the left and right sides of the front of the vehicle when the tire is traveling straight and when the tire is turning, and detects the lateral G from the difference.

8. 2. The physical quantity detection device according to claim 1, The physical quantity detection device is characterized in that the lateral G detection calculation unit determines that the lateral G has occurred when the change in the negative peak value between when the tire is traveling straight and when it is turning is 10% or more of the signal amplitude of the sensor signal waveform.

9. 2. The physical quantity detection device according to claim 1, The physical quantity detection device is characterized in that the lateral G detection calculation unit constantly compares the lateral G with characteristics stored in a table and detects the lateral G in real time.

10. 2. The physical quantity detection device according to claim 1, A physical quantity detection device characterized in that it is applied to improving the ride comfort of a vehicle equipped with the tire by performing suspension control based on the magnitude of the lateral G.

11. 2. The physical quantity detection device according to claim 1, A physical quantity detection device characterized in that the balance of the gripping force of the tire is changed by damper control based on the magnitude of the lateral force, and the physical quantity detection device is applied to safety support to prevent skidding of a vehicle equipped with the tire.

12. 5. The physical quantity detection device according to claim 4, a physical quantity detection device, characterized in that one of the two strain sensors is installed outside a center of an inner surface of the tire on the tire tread surface, and the other of the two strain sensors is installed inside a center of an inner surface of the tire on the tire tread surface.

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